Serum Levels of 25-Hydroxyvitamin D, Vitamin D Binding Protein, and Vitamin D Receptor in Type 2 Diabetes: A Case-Control Study from Libya

Abstract

Type 2 diabetes mellitus (T2DM) is a complex condition marked by disturbance in the way the body handles carbohydrate, lipid, and protein metabolism. 25 Hydroxyvitamin D (25(OH)D) is known to play an essential role in blood sugar regulation by influencing both insulin secretion and the body's response to insulin. This study aimed to evaluate the relationship between 25(OH)D, vitamin D-binding proteins (VDBP), and the Vitamin D Receptor (VDR) in Libyan Patients with T2DM. The study was carried out in Benghazi City between June 2022 and March 2023. A total of 44 patients with T2DM and 44 matched healthy controls, who had no history of T2DM. Clinical examinations and laboratory evaluations were performed on all subjects. Our study demonstrates a significant decrease (p<0.001) in the levels of 25(OH)D, VDR, Ca, P, and HDL-C in patients with T2DM compared to the control group. In contrast, no significant difference in the serum VDBP was observed between the two groups (P=0.07). In addition, patients with T2DM had remarkably high levels of (TC), (TG), and (LDL-c) compared to controls (p<0.001). Correlation analysis revealed a strong negative association between 25(OH)D and HbA1c levels (r = -0.737, p<0.05), alongside a strong positive correlation between 25(OH) D and VDR (r = 0.979, p<0.05). Vitamin D deficiency is a commonality in T2DM patients and is closely associated with poor glycemic control, however, due to the study’s cross-sectional design, causality cannot be inferred. These results emphasize the possible role of 25(OH)D in the pathogenetic mechanism, progression, and management of T2DM.